/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.mapred;

import java.io.IOException;
import java.io.DataInput;
import java.io.DataOutput;

import org.apache.hadoop.io.UTF8;
import org.apache.hadoop.fs.Path;

/**
 * A section of an input file. Returned by
 * {@link InputFormat#getSplits(JobConf, int)} and passed to
 * {@link InputFormat#getRecordReader(InputSplit,JobConf,Reporter)}.
 * 
 * @deprecated Use {@link org.apache.hadoop.mapreduce.lib.input.FileSplit}
 *             instead.
 */
@Deprecated
public class FileSplit extends org.apache.hadoop.mapreduce.InputSplit implements
		InputSplit {
	private Path file;
	private long start;
	private long length;
	private String[] hosts;

	FileSplit() {
	}

	/**
	 * Constructs a split.
	 * 
	 * @deprecated
	 * @param file
	 *            the file name
	 * @param start
	 *            the position of the first byte in the file to process
	 * @param length
	 *            the number of bytes in the file to process
	 */
	@Deprecated
	public FileSplit(Path file, long start, long length, JobConf conf) {
		this(file, start, length, (String[]) null);
	}

	/**
	 * Constructs a split with host information
	 * 
	 * @param file
	 *            the file name
	 * @param start
	 *            the position of the first byte in the file to process
	 * @param length
	 *            the number of bytes in the file to process
	 * @param hosts
	 *            the list of hosts containing the block, possibly null
	 */
	public FileSplit(Path file, long start, long length, String[] hosts) {
		this.file = file;
		this.start = start;
		this.length = length;
		this.hosts = hosts;
	}

	/** The file containing this split's data. */
	public Path getPath() {
		return file;
	}

	/** The position of the first byte in the file to process. */
	public long getStart() {
		return start;
	}

	/** The number of bytes in the file to process. */
	public long getLength() {
		return length;
	}

	public String toString() {
		return file + ":" + start + "+" + length;
	}

	// //////////////////////////////////////////
	// Writable methods
	// //////////////////////////////////////////

	public void write(DataOutput out) throws IOException {
		UTF8.writeString(out, file.toString());
		out.writeLong(start);
		out.writeLong(length);

		out.writeInt(hosts.length);
		for (int i = 0; i < hosts.length; i++)
			UTF8.writeString(out, hosts[i]);
	}

	public void readFields(DataInput in) throws IOException {
		file = new Path(UTF8.readString(in));
		start = in.readLong();
		length = in.readLong();
		// hosts = null;

		int numHosts = in.readInt();
		hosts = new String[numHosts];
		for (int i = 0; i < hosts.length; i++)
			hosts[i] = UTF8.readString(in);
	}

	public String[] getLocations() throws IOException {
		if (this.hosts == null) {
			return new String[] {};
		} else {
			return this.hosts;
		}
	}

}
